1. Field of the Invention
This invention relates to a shock absorber with a check valve and a check valve for a shock absorber. The check valve, possibly even a shutoff valve or non-return valve, is between two segments of a fluid connection, which connects two fluid chambers of a shock absorber with one another, whereby the check valve device with at least one check valve which separates a high-pressure segment and a low-pressure segment and has a checking body, can be adjusted between a closed and an open position by means of an external control via a magnet armature and a magnetic winding which is protected by means of a separator plate from the check valve, whereby a first side of the check valve pressurized by the high-pressure segment can be elastically pressed against a check valve seat which is a component of a pot-shaped insert, by means of a compression spring, also that a second side of the check valve body at some distance from this first side and adjacent to a control chamber is pressurized by the fluid pressure in this chamber, also that the control chamber is connected by means of a throttle section which bypasses the check valve body, also that the control chamber is connected by means of a control chamber discharge to the low-pressure segment, whereby there is a control chamber discharge valve with a control chamber discharge valve seat in the control chamber discharge, whereby the control chamber valve seat is configured on a supplemental discharge valve body, which together with a supplemental discharge valve seat on the check valve body forms a supplemental control chamber discharge of the control chamber, and that between the control chamber discharge valve body and the supplemental discharge valve body there is a coil compression spring which applies a prestress to the control chamber discharge valve body in the direction of lifting it from the control chamber discharge valve seat of the supplemental discharge valve body.
2. Background Information
Federal Republic of Germany Laid-Open Patent Application No. 41 14 305 discloses a check valve which, even after the magnet armature has been moved into the open position, only essentially switches from a hard damping force setting to a soft damping force setting when the pressure in the high-pressure section falls below a specified value. During tests on vehicles which have a particularly soft damping characteristic, unpleasant noises occurred which were caused by an unacceptable fluctuation of the damping force characteristic. In spite of the open position of the magnet armature, isolated damping force peaks were measured in the force-velocity diagram of a shock absorber equipped with such a check valve device.